Near Intersection of I-35 & I-90 Southern Mn. | First of all let's clarify a couple things. In a Raven Injection pump the Flow is calculated based on a sensor that measures the rotation of the pump shaft. This rotation is converted to a Flow Rate and Application rate based on the Flow Calibration number. The actual Flow rate for an injected product is not measured by a turbine flowmeter as is commonly done for the carrier. The reason being the problems associated with designing a flowmeter to accurately measure these small amounts.
For example if you are using a Meter Cal of 110, the Sidekick converts the number of pulses it receives from the shaft rotation sensor to ounces by dividing by 11.0. This calibration number varies slightly from pump to pump and somewhat for different products.
As long as the pump is not worn and the system is in good condition everything works out fine.
Raven also has two alarm features to warn you when there may be other problems. They are the Vac alarm and the Flo alarm. The Vac alarm consists of a sensor that detects excessive "suction" on the line leading to the inlet of the pump. This is to warn the operator that the suction line has some type of obstruction such as a plugged filter, kinked line or obstruction in the tank. If this excessively low vacuum is detected, the Vac Alarm sounds and the word Vac is shown on the display.
The Flo alarm is the other alarm and the one to which you refer. This is a device in the outgoing pressure line to warn the operator when the Flo is low or non present. In older Raven Injection pumps this was merely a sensor installed in the output line. This sensor contained a magnetic capsule and a spring. Without product flow the magnet would complete a circuit and warn the operator. With product flow, the magnet was displaced and compressed the spring. This opened the circuit and the alarm was not activated.
This approach was really not too realiable. In the modern Raven Injection Pump, there is a passage between the two cylinders of the pump. This passage has a shuttle sensor in it. Thus if there is good pumping action by both cylinders, there should be back and forth movement of product in this passage way. A sensor is mounted to watch this passage way. This is connected to the LED on the Sidekick display and also to the alarm circuit. As the pump is turning and pumping properly the LED should blink in direct proportion to the pump speed. If this does not happen often enough the Flo alarm is activated. If the pump is running rapidly, the LED will appear to stay lighted although it is actually going ON/OFF very quickly.
If all indications are good but you get the Flo alarm, the problem may be an adjustment of the shuttle sensor on the pump or a problem with this sensor. To adjust this sensor turn the three-way valve to return product to the tank and run the pump slowly in MANual. This will allow you to move the sensor and watch the LED on the sensor itself. Moving the sensor sidways in the slot may cure your problem.
I am a bit concerned about using a Redball Flow monitor with N-Serve and injection. We always use a Redball or equivalent in spray systems as a visual check that the product is in fact being pumped. However there may be some safety issues in using N-Serve and NH3.
The advice about checking the flow sensor and swapping it with one from a turbine flowmeter is sound advice but really does not apply in your situation since you indicate that the applied rate seems to be correct. The applied rate, totals etc are coming from that sensor. Your problem seems to be with the Flo Alarm portion of the system.
Once again there are two different meanings to the word Flo in injection pumps. One is the flow rate which is determined by the sensor that senses pump rotation. The other is a device to warn the operator when actual flow is not present.
Case in point - Suppose the tank ran empty. Obviously no product is being applied. The applied rate would appear fine since the pump would probably be turning at the proper speed. The Flo monitor however should sound since the shuttle sensor would not be moving back and forth.
Edited by tedbear 11/27/2007 07:12
|
sidekick injector
